Page:Transactions of the Geological Society, 1st series, vol. 4.djvu/284

From Wikisource
Jump to navigation Jump to search
This page has been proofread, but needs to be validated.

highly elevated, are in some parts vertical, while in others they incline, like the rocks by which they are accompanied, sometimes in one direction and at others in the opposite one, from the perpendicular, their bearing being north-easterly. Although the accompanying strata extend from one shore of the island to the other, the quartz rock in question does not attend them throughout, the total length which its leading mass occupies being limited to about five miles, as nearly as that can be ascertained. Its south-western end will be found in the hills behind the castle of Dunscaich, and its north-eastern approaches the shore of Loch Eishort, nearly opposite to a small island which forms the innermost harbour of that branch of the sea. The collective breadth of the strata where they are widest, appears to be about a mile and a half, while at each end it is much less, but the nature of the ground does not permit their whole extent or geographic shape to be accurately ascertained. In a general view they form two irregular ranges of parallel elevations, with shallow intermediate vallies, and as these summits maintain scarcely any vegetation, while they are composed of white compact quartz, their effect is very striking, even at a great distance; presenting the appearance of a fall of recent and thin snow.

Besides this leading mass, many detached portions of strata of the same substance are to be seen in the neighbourhood, and they are most accessible on the shore from Dunscaich to Ord. In these places their alternation with the red sandstone and greywacké schist can be traced with great ease and satisfaction, while at the same time their stratified disposition and their angles of inclination may be examined in considerable detail. The small island of Dunscaich, remarkable for the remains of a Danish strength, and a more probable residence of the traditional king of the Isle of Mist than the neighbouring promontory, affords particular facilities for examining